The Applicant has developed a wide range of printers that employ pagewidth printheads instead of traditional reciprocating printhead designs. Pagewidth designs increase print speeds as the printhead does not traverse back and forth across the page to deposit a line of an image. The pagewidth printhead simply deposits the ink on the media as it moves past at high speeds. Such printheads have made it possible to perform full colour 1600 dpi printing at speeds in the vicinity of 60 pages per minute, speeds previously unattainable with conventional inkjet printers.
Printing at these speeds consumes ink quickly and this gives rise to problems with supplying the printhead with enough ink. Not only are the flow rates higher but distributing the ink along the entire length of a pagewidth printhead is more complex than feeding ink to a relatively small reciprocating printhead.
The ink ejection nozzles are typically formed on printhead integrated circuits (ICs) using semiconductor fabrication techniques on a silicon wafer substrate. Supplying the printhead ICs with ink requires the ink conduits in the supporting structure to be correctly primed. As the width of each conduit is typically less than a millimeter, the ink can form a meniscus across a branch of the conduit network and the ink flow simply bypasses that branch (and therefore the nozzles on the IC that it supplies). In the case of pagewidth printheads, the problem is exacerbated by the length and complexity of the conduits.